Clarifying process for molasses



Patented'Jan. 23, 1940 UNITED STATES PATENT OFFICE CLARIFYING PROCESS Foa MoLAssEs Pater steiaaker, onde, Westphalia, Germany Application April 14, 1938,. Serial No. 201,997 In Germany April 30, 1937 1 Claim.

before the separation, either to take samples of dirt or as a precautionary measure to interrupt the centrifuging prematurely and to carry out a drum purification. It has therefore been proposed to clarify the molasses by centrifuging with continuous mud discharge, the material being at the same time divided into a pure nutrient solution and a dirt concentrate. For reducing the losses, the dirt concentrate is diluted with water and separated into a, clear and a dirty product in a second centrifuging operation. It is known that manyof the substances contained in the molasses, especially the inorganic substances, dissolve at higher dilution, and on this account the centrifugal clarification is usually carried out wth a dilution of about 40 Ball. On the other hand there are substances which are so finely distributed and of such a specific gravity that 'they can only be separated at slight concentration with an economically sufficient quantitative efficiency of the centrifuging machine.

The invention consists in that the known purification of the molasses by centrifuging is carried out in two stages at different concentrations, the material being purified the first time at higher concentration, preferably 40 to 50 Ball. and a second time at lower concentration, preferably 15 to 25 Ball. The result of a this procedure is, that the impurities, which dissolve at stronger dilution, are centrlfugally separated at higher concentration cf the molasses. This is preferably done in a centrifugal machine with very large mud space, because the percentage of these substances constitutes the major portion of the material. rIy'he molasses concentration is in this instance preferably about 40 to 50 Ball. or higher.

The molasses are diluted with water to a concentration of 15-25 Ball. immediately after the rst centrifugng operation. The final clarification takes place preferably at high speed and in a centrifuging drum with a high separating capacity, which drum must necessarily have a relatively small mud space. At the second centrifuging operation, however, only a very small mud 5 space is required because the percentage of the specifically lighter, mainly organic foreign bodies in the molasses is low. Subsequently the molasses flow into the fermentation vatV in a continuous stream or through` an intermediate vessel.

In view of the relatively small mud space available in the centrifugal drums hitherto generally employed the addition of admixtures forming precipitates to the molasses has hitherto been avoided and, for example, diammonium phosphate is employed instead of the superphosphates frequently used in a chemical pre-treatment in combination with the settling process. phosphate solutions have already `been added to the molasses before the centrifugal clarification, but then either the superphosphate solution was allowed to stand so that the foreign substances could settle on the bottom or the centrifugal clarification was interrupted and repeated drum clarification carried out. The great advantages offered Aby the centrifugal clarification in the preparation-of the molasses for the manufac- Superture of pressed yeast were thereby not fully utia lized.

According to the invention however, it is possible, to mix the superphosphate solution directly with the molasses without allowing it to stand o'r without clarification by any other means, because the mud space of the pre-clarifying centrifuge is sufficiently large to also accommodate the impurities also separating out of this nutrient substance.

A plant for carrying out the invention is illustrated by way of example in theaccompanying drawing.

The concentrated molasses iiow out of the vat A through a coarse strainer B and a measuring instrument C for measuring the quantities fiowing through the large space centrifuge D. The centrifuged molasses encounters through an inspection glass E flowing along the conduit F the fresh water conduit G and is thus diluted according to the given proportion, After the quantity of diluted molasses has been ascertained by a through-now meter H, the molasses flow to the fine clarifying centrifuge J. The finished clarified molasses are conducted through an inspectrifuging action being executed in two stages in the first of which the molasses are initially centrifuged in-a highly concentrated state of about 40 to 50 Ball. to eliminate the heavy mud therefrom, whereasvin the second stage the molasses are, after dilution with water, centrifuged in a. state of low concentration of about 15 to 25 Ball.

PETER s'rnmacxaa. 

